High-intensity Nd:YAG laser accelerates bone regeneration in calvarial defect models

• Published in: Journal of tissue engineering and regenerative medicine Vol. 9; no. 8; pp. 943 - 951
• Main Authors: Kim, Kwansik, Kim, In Sook, Cho, Tae Hyung, Seo, Young-Kwon, Hwang, Soon Jung
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.08.2015; Hindawi Limited
• Subjects: Aluminum; Animals; Bone and Bones - diagnostic imaging; Bone and Bones - radiation effects; bone regeneration; Bone Regeneration - radiation effects; calvarial defect; Collagen - chemistry; collagen sponge; Fracture Healing; high intensity; high power; Imaging, Three-Dimensional; Lasers; Lasers, Solid-State; Male; Nd:YAG laser; Neodymium; Rabbits; Rats; Regenerative medicine; Tissue engineering; X-Ray Microtomography; X-Rays; Yttrium; Nd:YAG laser; bone regeneration; collagen sponge; high power; calvarial defect; high intensity
• ISSN: 1932-6254; 1932-7005
• DOI: 10.1002/term.1845

High‐power pulsed lasers have been recently regarded to be anabolic to bone, but in vivo evidence is still lacking. This study aimed to investigate the capacity of bone repair using a high‐power, Q‐switched, pulsed, neodymium‐doped yttrium aluminium garnet (Nd:YAG) laser, using bilateral calvarial defect models having non‐critical sized, 5 mm (rat) or 8 mm (rabbit) diameter. One of the bilateral defects, which were all filled with collagen sponge or left empty, was irradiated with a Nd:YAG laser once every 2 days for 2 weeks at a constant total fluence rate (344 J/cm2), output power (0.75 W), pulse repetition rate (15 pps) and wavelength (1064 nm) and examined for the laser effect. The same experimental scheme was designed using a rabbit calvarial defect model implanted with sponge, which was explored for the dose effect of output power at 0.75 and 3 W with the same quantities of the other parameters. New bone formation was evaluated by micro‐computed tomography‐based analysis and histological observation at 4 weeks after surgery. Laser irradiation significantly increased new bone formation by approximately 45%, not only in the sponge‐filled defects of rats but also when the defects were left empty, compared to the non‐irradiated group. Consistently, both doses of output power (0.75 and 3 W) enhanced new bone formation, but there was no significant difference between the two doses. This study is one of the first to demonstrate the beneficial effect of Nd:YAG lasers on the regeneration of bone defects which were left empty or filled with collagen sponge, suggesting its great potential in postoperative treatment targeting local bone healing. Copyright © 2013 John Wiley & Sons, Ltd.